Hybrid vehicles are attracting attention as environment-friendly vehicles. A hybrid vehicle incorporates a power storage device, an inverter, and an electric motor driven by the inverter, in addition to a conventional internal combustion engine, as the power source for traction.
Japanese Patent Laying-Open No. 2007-62640 (PTL 1) discloses such a hybrid vehicle having the vehicle running mode switched based on the SOC (State of Charge) of a power storage device. The driver of the hybrid vehicle sets the target SOC taking into account the power usage state at the destination. The period starting from running in which the SOC of the power storage device was at a fully charged state and before the SOC reaches the target SOC is referred to as a running mode in which the engine is stopped and running using the motor generator alone is given priority (hereinafter, referred to as “CD (Charge Depleting) mode”. When the SOC reaches the target SOC, the vehicle moves to a running mode in which the engine is operated and the SOC is regulated at the target SOC (hereinafter, referred to as “CS (Charge Sustaining) mode” (refer to PTL 1).